I found a problem with the unattended-uninstall.cmd script on Windows 7, where the system would randomly lock the ..\VideoLAN\VLC\uninstall.exe file after installation (download handle.exe from here to verify the lock: http://technet.microsoft.com/en-us/sysinternals/bb896655). This lock then prevents the new install to overwrite the uninstall.exe. The result being that the uninstall.exe file "disappears" after the lock has been released. Any future attempts to run the unattended.cmd would then fail because the uninstall.exe is missing...

To fix this problem, in unattended-uninstall.cmd change the for loop to: